The present invention relates generally to magnetic remote control switches and more particularly to low voltage transformer relays.
A variety of magnetic remote control switches exist in the art. Some of these magnetic remote control switches incorporate a transformer along with an electromagnetic structure. Such a combination structure allows a switching system to be remotely controlled from low voltage switches connected to the secondary of the transformer. Typically, these structures are then called low voltage transformer relays.
Two primary examples of these low voltage transformer relays are described in U.S. Pat. No. 3,461,354, Bollmeier, Magnetic Remote Control Switch and U.S. Pat. No. 4,321,652, Baker et al, Low Voltage Transformer Relay. In both structures a transformer is provided within an electromagnetic structure. The transformer has a primary winding (coil) and a secondary winding (coil). The primary winding is connected to a source of alternating current, e.g. a 60 hertz power source. The electromagnetic structure contains an armature which is magnetically stable in either of two positions. The armature carries or activates a set of contacts which contains load carrying contacts. With the secondary winding of the transformer open, the electromagnetic device remains stable in its prior position. Bidirectional switches can be coupled in parallel, either directly or through an interface circuit, to the secondary winding of the electromagnetic device. The bidirectional switches can be activated to restrict the current flowing in the secondary winding to either a first or a second direction switching the transformer relay to either a first or a second position, thus operating the load carrying contacts.
Both the Bollmeier and Baker et al low voltage transformer relays are constructed in a three leg configuration with an armature mounted for movement between opposed pole faces. One leg of the ferromagnetic core contains the primary winding or coil, a second leg of the ferromagnetic coil contains a secondary winding or coil. The third leg contains a gap defined by opposed pole faces with the armature disposed in the gap between the opposed pole faces.